Piston for internal combustion motors



July 14, 1936 E c, L NG 2,047,788

PISTON FOR INTERNAL COMBUSTION MOTORS Filed July 29, 1932 INVENTORATTORNEY Patented July 14, 1936 UNITED STATES Ass eerie];

PISTON FOR INTERNAL COMBUSTION MOTORS 4 Claims.

This invention relates to an improvement in pistons of the typegenerally made of aluminum alloys and pertains more particularly topistons used in internal combustion motors in which the heat of themotor is an essential to be taken into consideration with respect topistons of this character, the invention in this application being afurthering of the inventions contained in my co- .pending applicationsSerial Nos. 281,175 and 339,892 filed March '7, 1919 and November 22,1919 respectively.

The primary object of the invention is to provide a piston of animproved construction with means whereby a part of the piston skirt willbe held against normal expansion.

Another object of the invention is toprovide a piston with a structureextending from the head to a part of the piston skirt whereby expansionof the head will cause the skirt part to be held 20 against moving toofar outwardly by expansion.

A further object of the invention is to provide a piston with aseparated or cut away part in the periphery of the skirt with meansextending from the head to the separated part which is made 25 coaotableon the part when the head is expanded by heat.

Other and further objects will appear in the specification and bespecifically pointed out in the appended claims, reference being had tothe ac- 30 companying drawing, exemplifying the invention,

and in which:--

Figure 1 is a side elevation of this improved piston.

Figure 2 is a vertical section taken approxi- 35 mately on the line 2-2of Fig. 1.

Figure 3 is a vertical section taken approximately on the line 33 ofFig. 2.

Figure 4 is an end elevation of the piston. Figure 5 is an invertedhorizontal section taken 40 approximately on the line 5-5 of Fig. 2.

Figure 6 is an inverted horizontal section taken approximately on theline 6-6 of Fig. 3.

Referring by numerals to the accompanying drawing, I designates the headof a piston having 45 a side wall 2 in which the packing ring recesses 3are formed, and depended from the side wall 2 is a skirt 4, said skirtbeing larger in diameter across its thrust sides than is the diameter ofthe side wall 2 of the head.

50 The pin boss sides 5 of the piston are each provided with a pin bossI5 and extending across the head I interiorly thereof are a plurality ofwebs I, said webs at their ends extending downwardly to respective pinbosses and are formed integral with the head, the pin boss sides and thepin bosses. The skirt 4 on each of its pin boss sides is provided with arelief 8.

The skirt 4 on one of its thrust sides is provided with a separated orcut away part 9, said part 9 being formed by providing a slot or gap 5Iii on the pin boss sides 5 of the piston adjacent and around respectivepin bosses and said slots being oppositely disposed. The slots II] areintersected beneath respective pin bosses by a slot Illa which extendsfrom the open end of the piston, 10 and the slots I0 at their upper endsjoining the transverse slot I I which is formed in the side wall 2 0f.the head.

The cut away part 9 is supported in approximate peripheral alinementwith the skirt 4 by a bridge structure I2, said bridge structurecomprising an arcuate wall l3 extending from the pin boss sides 5 of thepiston on the interior thereof and also being connected with respectivepin bosses 6, said wall It extending longitudinally in the piston andbeing joined to the cut away part 9 by a pair of diverging webs M.

The wall it and the inclined webs l4 connecting said wall and the cutaway part 9 of the skirt 4 in the casting operation of the piston areextended to the head I of the piston as shown in Fig. 3 and in machiningthe piston, the gaps I0, Illa and adjoining transverse slot I I aremade, the cutting operation when making the transverse slot II cuttingthrough the arcuate wall I3 and joining webs l4 (see Figs. 3 and 6).

The extending of the wall l3 and the webs I4 to the piston head I andthe arrangements of the plurality of webs l from the head to the pinbosses, provides a piston which can be readily die-cast with simplicityowing to the fact that means are provided for the dropping orwithdrawing of cores from the molded piston.

After the machining or finishing of the piston and the skirt of thepiston has been finished to 4 an approximate .002 clearance for fittingthe piston in the cylinder of an internal combustion motor, the closeclearance given is sufficient to prevent piston-slap of the piston inthe cylinder in the starting of the motor or when the motor is runningcold. Upon heated conditions within the cylinder, the head I by reasonof receiving the expanding burning thrusts from gaseous charges willobviously receive a maximum of heat and consequently have maximumexpansion. As the head expands, the opposing pin bosses 6 beingconnected with the side wall 2 of the head I will be moved outwardlywith the expanding forces of the head and as the arcuate wall I3 isconnected to the pin boss sides of the piston and the pin bosses, theoutward movement given to the pin bosses from the head will tend tostraighten or lengthen the Wall l3 and in so doing will pull theintermediate portions of the wall towards the pin bosses and as the wallI3 is connected to the cut away portion 9 by the webs M, the portion 9will be pulled inwardly rather than be permitted to be moved outwardly.

The holding in or pulling in of the cut away part 9 of the skirt 4during expansion of the piston and particularly the head of the pistonwill obviously eliminate and consequently prevent any excess expansionof the skirt on a diameter across the thrust sides of the piston andtherefore there will be no seizing of the skirt in the cylinder as theskirt on the pin boss sides 5 is relieved as indicated at 8.

Attention is called to the inclination of the webs Hi from the arcuatewall I3. This is for the purpose of causing the end portion l5 of thecut away part 9 to be held or pulled inwardly during the expanding ofthat portion of the cut away part 9 between the points of connection ofthe webs I4 therewith.

Oppositely disposed in the skirt 4 from the cut away part 9 is a partl6, said parts forming thrust sides in the skirt, the part it difieringfrom the part 9 in that the part 9 is entirely cut away from the skirtand whereas the part H5 is integral with and depends from the side wall2 of the head as shown at I! in Figs. 1, 3, and 6. Inasmuch as the parti6 is cut away from the part 9 by the slotting l and Illa, reinforcingmeans in the form of webs l8 are extended from the pin bosses 6 to thepart l6, there being a web is from each pin boss to the part IE5. Whilethe part Hi depends from the portion ll, the portion I1 is maderelatively narrow in circumferential length by the transverselyextending slotting H a on each pin boss side of the piston, saidslottings I la extending from the slottings 10. This is for the purposeof making the part 16 yieldable for permitting free expansion andcontraction of said part under thermal conditions.

Obviously constructional modifications of the device are possiblewithout departing from the spirit of the present invention and thereforeit is to be understood that it is not necessary to limit the inventionby the terms used in the foregoing description, excepting such as thestate of the art may require.

What I claim is:--

1. A one-piece piston comprising a head having a side wall and a skirthaving opposed thrust sides, one of the thrust sides being separatedfrom the side wall of the head and the other thrust side beingcontinuous with the side wall of the head, opposed pin boss sidesdepending from the side wall of the head and separated from the thrustsides of the skirt, a pin boss extending from each pin boss side, atransversely extending wall joined at its ends with respective pinbosses, and connectors extending from said wall to the separated thrustside of the skirt.

2. A one-piece piston comprising a head having a side wall and a skirthaving opposed separated thrust sides, one of the thrust sides beingseparated from the side wall of the head and the 10 other thrust sidebeing continuous with the side wall of the head, opposed pin boss sidesdepending from the side wall of the head and separated from the thrustsides of the skirt, a pin boss extending from each pin boss side, atransversely extending wall joined at its ends with respective pinbosses, a pair of connectors joined with and diverging from said walland being connected at their extending ends with said disconnectedthrust side of the skirt, and supporting means extending from each pinboss to the other thrust side of the skirt.

3. A one-piece piston comprising a head having a side wall and a skirthaving opposed separated thrust sides, one of the thrust sides beingdisconnected from the side wall of the head and the other thrust sidebeing continuous with the side wall of the head, opposed pin boss sidesdepending from the side wall of the head and separated from the thrustsides of the skirt, a pin boss extending from each pin boss side, atransversely extending arcuate wall joined at its ends with respectivepin boss sides and respective pin bosses, a pair of walls joined withand diverging from said arcuate wall and being connected at theirextending ends with said disconnected thrust side of the skirt, andsupporting means extending from each pin boss to the other thrust sideof the skirt.

l. A one-piece piston comprising a head having a side wall and a skirthaving opposed separated thrust sides, one of the thrust sides beingdisconnected from the side wall of the head and the other thrust sidebeing continuous with the side wall of the head, opposed pin boss sidesdepending from the side wall of the head and separated from the thrustsides of the skirt, a pin boss extending from each pin boss side, atransversely extending arcuate wall joined at its ends with respectivepin boss sides and respective pin bosses, a pair of walls joined withand diverging from said arouate wall and being connected at theirextending ends with said disconnected thrust side of the skirt, and aweb connecting each pin boss to the thrust side of the skirt which iscontinuous with the side wall of the head.

ELMER C. LONG.

